Push type fluid conveyor



3 Sheets-Sheet l Filed Jan. 12. 1951 PRUDUL T WIPO/2 OIL Feb. 28, 1956 A. J. wEsH PUSH TYPE FLUID CONVEYOR Filed Jan. l2. 1951 l l f l Irl 1 l MM 4K 417 I''l'rlllf'f 52 A I iii;

"I' .u #j U 5 sheets-sheet 2 AGENT Feb. 28, 1956 A. J. wEsH PUSH TYPE FLUID CONVEYOR 3 Sheets-Sheet 3 Filed Jan. 12, 1951 IN VEN TOR. Hai/:011g f /ZSI/ 6E/V T H//e 00T SOL/DS /N 97 PUSH TYPE FLUID CONVEYOR Anthony J'. Wash, Woodbury, N. J., assigner to Socony Mobil Oil Company, Inc., a corporation of New York Application January 12, 1951, Serial N0. 205,654

7 Claims. (Cl. $02-$17) This application is ydirected to the conversion of hydrocarbons in the presence of a hot particle-form solid contact material. lt is more particularly concerned with the lifting of hot comminuted solid material in a continuous hydrocarbon conversion process.

It is well known in the art that hydrocarbons can be converted by contacting them at a suitably high temperature with contact material for an appropriate period of time. The contact material may be catalytic in nature or may be a substantially inert material. For example, solid particles of silica, alumina, or silica and 'alumina have been used successfully to catalytically cause the conversion of hydrocarbons, such as gas oil, to more useful products, particularly gasoline boiling compounds. Other materials, such as natural or treated clays or inert refractory materials, such as corhart, mullite and the like have been used successfully in various types of hydro-Y carbon conversion processes.

During the conversion, 'the 'solid contact material is partially or completely covered by a coke or carbonaceous formation which interferes with the proper operation of the particles. When inert particles are used as heat carrying members, they give up their heat in the conversion zone while they are being covered with carbonaceous material. It is necessary to 'remove 'the carbonaceous deposits when the free Isurface of the particles is materially reduced, or, in the case yof inert material, to reheat the particles. In the continuous processes of hydrocarbon conversion this is accomplished by removing continuously a portion of the contact material to a burning zone where the deposits are removed by burning, and supplying either fresh or restored particles continuously to the reaction zone. For example, the particles removed from the reaction zone are conveyed to the burning zone and the restored particles removed from the burning zone are conveyed to the reaction zone to complete the cycle. In a preferred system of hydrocarbon conversion, mechanical elevators of the bucket type have been used to lift the hot contact material. In operating these elevators, it has been necessary to keep the temperature of the contact material beingr conveyed below a maximum limit which will cause the moving parts of the elevator to overheat and jam. This has been accomplished by the use of heat exchangers, or the addition of steam to the contact material before it is introduced into the elevator.

This is particularly disadvantageous in certain processes, because it involves an uneconomical Waste of heat. This is illustrated in the conversion of higher boiling hydrocarbons to the highly 'useful Vproduct ethylene 'by reaction for a very short time, `say 0.2 second, at high ternperatures on the order of 1500 F. 'and above'. To obtain the necessary short reaction time, the high 'temperature reaction mixture must be promptly quenched to a low temperature. One advantageous -system for -accomplishing this high temperature short vtime reaction "is to' pass the charge hydrocarbons in direct contact with a bed of highly .heated granular solids and then :pass :the h'o't reacf ited States Patent O tion mixture through a bed of relatively v.cold :granular 2,736,611 Patented Feb. 28, 1956 solids. This requires two contacting chambers connected by a transfer line which will confine the hot gaseous mixture within a predetermined path. The hot particles are removed from the reaction vessel, partially or completely covered 'with carbonaceous material, as a substantially solid column of coarse size material. The hot coarse particles are cooled, according to the prior art, prior to being admitted to an elevator. The particles are discharged from the top of the elevator into a burner, into which fuel is sprayed to burn with air in the burning oi of the carbonaceous deposits from the particles, and also provide the extra heat needed to raise the temperature of the Contact material to the high temperature required in the reaction vessel. The hot particles are withdrawn from the bottom of the heater and introduced into the top of the reaction vessel, located below, as a substantially compact column. As seen, the process wastes heat in that the reaction is endothermic and the burning is exotherrnic and yet heat is continuously removed after the endothermic reaction and supplied during the burning reaction.

The object of this invention is to provide a more eiiicient system and apparatus for hydrocarbon conversion.

Another object of this invention is to provide improved apparatus and process for the hydrocarbon conversion of gas oils to ethylene.

Another object of this invention is to provide a means and method of lifting high-temperature coarse solid particles of contact material used in the conversion of hydrocai-bons.

Another object of this invention is to provide an improved method of and apparatus for pneumatically lifting granular solids.

These and other objects will be made apparent in the following discussion of the invention. The invention will be described in detail with reference to the attachedv sketches, in which Figure l is a diagrammatic showing of the relationship of the several elements Amaking up a plant for this purpose.

Figure 2 .is `a vertical elevation, partially in section, of the lifting means disclosed by this invention.

Figure 3 is a sketch of the lower portion of the lifting means disclosed by this invention.

Figure 4 is a View, partially in section, of alternate feeding means disclosed by this invention.

Figure 5 isa view,`in section, of alternate lifting means.

Fisgure I6 is a plan view, as seen on plane 6 6 of Figure Referringspecitically now to Figure l, ahot granular solid, preferably of a particle size of about 3-40 mesh Tyler screen analysis, although other sizes may be utilized, is heated to a suitable high temperature in heater 10 and transferred `by feed vleg 11 through a steam sealing zone 12 to aV reactor 13. A charge for the reaction is lintroduced by a plurality `of inlet tubes 14 depending from .ring manifolds 15 at the top of the reactor. The number and :spacing of Itubes 14 is such as to give uniform spacing .of the discharge openings at the bottom ends thereof, depending on the size and shapev of the cross-section of reactor 13. A typical structure has an internal diameter of reactor shell of six feet nine inches 'with la dellectin'g insert centrally llocated in the vessel of two feet. Three concentric rings'of tubes 14 contain 11, 18 and 23 tubes, respectively, which depend into the bed of ygranular ymaterial surrounding the insert. The charge may advantageously be a liquid oil, mixed with liquid water,y to generate the yhydrocarbon and steam vapors desired for 'the reaction. Alternatively, hydrocarbon and steam vapors may vbe generated outside the reactor `and lcharged thereto as a vapor phase mixture;

.Within the .reactor 13 the charge-- is passed yin direct contact with the highly heated granular solids and is thus rapidly converted to a vapor phase mixture having the temperature desired for the reaction. Upon leaving the contact bed, the reaction mixture is quenched by the injection of water supplied from the inlet 16 and is passed by the conduit 17 to a quencher 18 wherein it is passed through a moving bed of relatively cool granular solids for further reduction of temperature. The quenched reaction mixture is transferred by line 19 to a spray condenser 20 from which product vapors are taken overhead by line 21 to a suitable gas plant for purification and recovery of the gaseous products of the reaction. Oil and water from the bottom of condenser 20 are passed to a settler 22 wherein they separate into an upper oil layer which is cooled in heat exchanger 23 before transfer to processing or storage and a lower water layer which is cooled in heat exchanger 24 to be recycled in part to the spray condenser by line 25. If the charge to the reactor is in liquid phase, water from the bottom of settler 22 may be used in the charge since contamination of the charge water has no detrimental etect in such operations, the contaminants being either vaporized with the water or deposited on the granular solid from which they may be removed by burning in the heater.

Returning now to the reactor 13, a purge gas such as steam is admitted to the bottom of the reactor at inlet 26 to prevent the hydrocarbons from passing downwardly through the bed, and through the lower outlet. A pressuring medium, which may be steam, is admitted at inlet 27 to prevent the hydrocarbons from entering the insulation on the inner walls of the vessel. The granular solids are withdrawn from the bottom of the reactor 13 by pipe 28 at a temperature of about l300 F. and are passed downward to the feeding chamber 30. Inasmuch as the feeding chamber 30 may be under considerable pressure, such as, about 50 p. s. i., a downwardly directed feed leg may be required between the bottom of the reactor and the chamber 30. Such a feed leg is shown and claimed in the copending application for Letters Patent Serial Number 108,828, led August 5, 1949, now abandoned. The coarse particles are lifted by the lifting device, disclosed hereinafter, through the lift conduit 31 to the disengaging chamber 32, located at the top. The lifting device is shown in greater detail on Figure 2.

Referring now to Figure 2, the granular material is introduced into the feeding chamber 30 as a substantially compact column, and enters the annulus 33. At the base of the annulus 33 is located a ring manifold 34 with a series of upwardly directed orices 35 located therein. The manifold is charged with a primary suspending gas by the conduit 35a from a source not shown. This gas may be any substantially inert gas or vapor, such as steam, or Hue gas. It is possible to use air or hydrogen for this purpose; however, the other fluids mentioned are preferred. Sucient uid is admitted from the manifold ring 34 to produce a very dense suspended phase with a level at or about the top of the barrier 36. The barrier 36 is an imperforate cylindrical wall open at the top, the top generally being somewhat higher than the inlet orice of the conduit 28, though this is not absolutely essential. A stream of secondary suspending gas is introduced through an upwardly directed conduit 37.

The lift device comprises essentially ascending leg 38 and descending leg 39 of smaller diameter than the ascending leg 3S. The legs are located substantially vertical in side by side relationship, and are firmly connected together by connectors 75, 75, located at spaced distances along the height of the legs. Upper boot 41 connects the upper ends of the legs and lower boot 42 similarly connects the lower ends of the legs. The boots have a generally gradually changing cross-section which is adapted to accommodate the change in inside diameter between the two legs. Within the descending leg is located a stack of spherical balls, located one on top of another, and of such size as to substantially fill the crosssection of the descending leg. The balls are made of durable metal, preferably. The balls may be solid or preferably of hollow construction. Within the feeding chamber 30 is horizontally mounted for rotation a ser rated wheel 44, adapted to retain one or more of the balls 43. The upper wall of the lower boot 42 is cut away suiiiciently to allow the serrated wheel to engage the balls, and the lower wall of the boot 42 is cut away in the region above the barrier 36. The boot is so shaped, however, that the balls 43 cannot escape from their generally enclosed path. The baffle 40 in the disengaging chamber 32 is adapted to direct the balls as they issue from the upper end of the ascending leg 33 toward the upper boot 41, which connects with the descending leg 39. The screen 29 provides a sloping oor for the balls, directing them toward the upper boot 41. The mesh of the screen is large enough to permit the particles to pass therethrough.

The operation of the lift will now be disclosed. The primary suspension gas is first introduced through the orices 35 and solid contact material is admitted through conduit 28 by opening the valve 45, forming a dense bed of suspended granular material. The secondary suspension gas is then introduced through the conduit 37, exiting from the disengaging chamber 32 through the conduit 46. When equilibrium has been reached in the feeding chamber 30, with a layer of less dense suspended contact material located in the region above the barrier 36, the wheel 44 is rotated, by means not shown, forcing one of the balls into the region above the barrier. Because of the large particle size, it is impractical to attempt to lift the contact material by the gas unaided, and hence the particles are merely oating when the ball is pushed into position above the barrier. The ball presents a substantially impervious wall across the ascending leg and hence a large pressure drop develops across the ball, lifting the ball up the leg and pushing before it a quantity of the floating contact material. The inside diameter of the ascending leg is made sufficiently larger than the diameter of the ball to permit enough uid to pass the ball for maintaining the particles in suspension above the ball. In some instances, particularly with the larger particle-size material, there develops a tendency for the particles to gather and pack, causing the balls to jam. This can readily be overcome by introducing additional suspending gas at spaced locations along the ascending leg through the conduits 47. These conduits are directed in a generally upward direction on alternate sides of the conduit, thereby maintaining the fluid dispersion substantially uniform.

At the top of the ascending leg, the contact material settles in the disengaging chamber whereas the balls roll off by gravity to leg 41 over a screen that permits the contact material to pass through. The gas ows upwardly in the disengaging chamber around the baffle 48 and out the conduit 46. The balls tit snugly in the descending leg creating a series of large pressure drop gaps, thereby effectively preventing the suspending gas from passing upwardly through the descending leg.

Thus, although the velocity of the gas passing upwardly through the ascending leg is below that required to lift the particles of contact material unaided, the presence of the balls in the leg enables the particles to be lifted. There is thus effected by this invention, a considerable saving in gas flow in addition to other advantages. For example, when it is attempted to raise the coarse particles by gas ow alone, the problem of disengagement of the particles from the gas in the upper boot is complex. The particles are fractured by being hurled against the metal walls of the boot producing excessive amounts of undesirable fines. This invention enables much lower avaaer 1 5 gas flow rates to be used, providing amore simple disengagement of particles from the gas in the boot, with substantially less damage to the particles.

Referring once again to Figure l, solid particles are discharged from the disengaging chamber into a feed pipe 49 as a substantially compact column and are then fed onto the top of a bed of the granular material in the heater to again pass through the cycle. In the heater, fuel from inlet 51 is burned in preheated air supplied at 52 to generate a flame in direct contact with the solid granules and thus heat the latter to the desired degree. When equilibrium conditions have been reached, it is an advantage of this invention over the prior art that the addition of fuel at this point may be materially reduced or discontinued completely. Flue gases are withdrawn at 53 and passed to an economizer or stack.

The quencher is an element of a similar cycle of granular solids wherein the granulesl serve to cool vvaporous reaction mixture from the reactor 13 and are then purged by steam admitted at 54 and passed by pipe 55 to the feeding chamber 57 of a lifting device similar in constructionto that previously disclosed. The particles pass up the ascending leg 58 to the disengaging chamber 59 under the impetus of the free floating balls, not shown. The balls, thereafter, continue in their substantially enclosed path down the descending leg 60. The primary suspending gas is admitted to the feeding chamber 56 through the conduit 61 and the secondary suspending gas is admitted through the conduit 62. Additional suspending gas can be admitted to the ascending leg 58 through the conduit 63. From the disengaging chamber 59, the solid particles are discharged by pipe 64 to a hopper 66. Solids are supplied through feed leg 67 to an air preheater 68 wherein they are contacted with air from blower 69 to preheat the same. The preheated air is then transferred by line 70 to inlet 52 of heater 10. Any carbonaceous deposit in the nature of coke or tar laid down on the solids in the quencher 18 will be burned olf in heater 68 by a large excess of air supplied to the chamber 68 and the net effect is to cool the solids in chamber 68 whereupon the cold granules are transferred by feed leg 71 through a steam purging zone 72 to the quencher 18.

As previously noted, one advantage of the disclosed lifting device is that the particles need not be cooled before being admitted to the lift. As shown on Figure 2, the ascending and descending legs may be lagged with insulation material 73 to prevent the waste of heat energy.

The serrated wheel 44 s'hown on Figure 2 may be driven by any suitable prime mover, such as an electric motor, which may be controlled at a uniform speed to properly space the balls in the ascending leg. Although the feeding means shown on Figure 2 is adequate for the purpose, other means of feeding the balls are possible. For example, the system shown in Figure'3 may be used, where only a portion of the ascending leg and descending leg is shown. In this embodiment the contact material is fed through conduit 28 to the annulus surrounding the barrier and suspended by gas admitted through the conduits 74, 75a. The feeding chamber 76 is shaped to form a substantially enclosed conduit in which plunger 77 is adapted to reciprocate. The plunger 77 is connected to the connecting rod 78, which is adapted to pass through the stuing box 79. The connecting rod 78 is attached to the crankshaft 80, which in turn is connected to the flywheel 81 by means of the crankpin 82. Continuous rotation of the flywheel by a suitable prime mover, such as an electric motor 83, introduces the balls singularly to the entrance of the ascending leg 38 at spaced intervals suitable for the lifting of the contact material.

It is possible, in a less preferred form of the invention, to use solid balls so dense that they will not float in the region above the barrier, or just below the ascending leg. In such a case, it is necessary to incorporate a retaining basket or support attached to the plunger 77 to prevent the balls from moving downwardly in the suspending region. A retainer with a hole in the bottom not large enough for the ball to fall through, and yet of such a shape that substantially all the suspending gas llows through the hole when the plunger is inthe extended position permits the dense balls to be lifted upwardly through the ascending leg. When light balls are used which float in the suspending region, these precautions need not be taken.

It is possible to use other members to move the contact material than free-floating balls such as shown on Figures 5 and 6. For example, round discs or rectangular plates can be utilized, connected by flexible connecting chains 96 for proper spacing in the ascending leg 97. This obviates the necessity of a feeding device, shown in the other embodiments. In order to prevent the discs from cocking and jamming in the conduits, it is preferred that the discs be locked on suitable tracks 98 fastened to the inner wall of the conduits and upper and lower boots or connecting members. The discs `can move freely on the tracks, but rotation about any axis passed through the disc is prevented by the tracks. Of course, if connecting chains or flexible connectors are not used to space the discs, feeding apparatus for feeding and spacing the discs must be used. It is not intended that the invention be limited to lifting members of any particular shape, although spherical balls are preferred. However, other shapes are contemplated, Vsuch as lifting members of a generally cylindrical shape.

Figure 4 shows an alternate feeding arrangement. In this embodiment the particle-form material is gravitated as a substantially compact column through the leg 28 into the tank 80. The'material is discharged onto the surface of a bed of the material in the feed vessel. The ascending leg 38 terminates at its lower end at a location intermediate the top and bottom of the vessel at a level below the surface of the granular bed. A primary gas pipe S1 is terminated within the tank 8@ at a location below the leg. The gas discharged from the primary gas pipe passes up the leg without passing through any of the bed of particulate material. A ring baffle 83a is located in the tank at the level of the bottom of the ascending leg, so as to form an annular region about the bottom of the leg through which the granular material gravitates. A secondary lift gas is introduced through the pipe 82 into the region behind the baille 83a. The gas passes around the bottom of the baille and through a substantial thickness of the bed before reaching the bottom of the ascending leg, whereby particles are pushed into the primary stream. The particles are suspended by the gas in the lower portion of the leg but are too dense to be lifted up the leg. The spherical balls 43 drop downward from the leg 39 into the conduit 42, which slopes laterally toward the ascending leg 38. A reciprocating piston 77 transfers the balls downward consecutively into the ascending leg, trapping a portion of suspended granular material in the leg above the ball. The pressure drop across the ball is sufficient to lift the ball and in addition the particles above the ball. The reciprocating piston may be operated by a motor, as shown on Figure 3, so as to space the balls in the ascending leg.

This invention is not intended to be limited to the specific embodiments shown above, being broad in its application and intended to cover all changes and modifications of the examples of the invention herein chosen for purposes of disclosure, which do not constitute departures from the spirit and scope of the invention.`

I claim:

l. Apparatus for lifting particle-form solids comprising ascending and descending legs, a series of lifting members located in said descending leg, means for feeding a lifting member to the region of the bottom of said ascending leg, means for suspending the particle-form solids in the region of the lower end of the ascending leg including means for feeding suspending gas to said ascending leg to assist in conveying said particle-form solids and said lifting members from'the bottom to the top of said ascending leg, means for withdrawing particle-form solids from the top of said ascending leg, means for withdrawing suspending gas from the top of said ascending leg, and further means for conducting the lifting member from the top of the ascending leg to the top of the descending leg.

2. Apparatus for lifting granular solid material comprising ascending and descending legs, a series of lifting members located in said descending leg, the cross-section of said lifting members being almost equal to the crosssection of the descending leg, the ascending leg having a cross-section somewhat larger than that of the descending leg, means for suspending the granular material in the region of the lower end of the ascending leg including means for feeding suspending gas to said ascending leg to assist in conveying said granular material and said lifting members from the bottom to the top of said ascending leg, means for feeding a lifting member from the bottom of said descending leg to the region of the bottom of said ascending leg, means for withdrawing granular material from the top of said ascending leg, means for separately withdrawing suspending gas from the top of said ascending leg, and further means for conducting the lifting member from the top of the ascending leg to the top of the descending leg.

3. Apparatus for lifting granular solid material comprising ascending and descending legs, a series of lifting members located in said descending leg, the cross-section of said lifting members being slightly smaller than the cross-section of the descending leg, the ascending leg having a cross-section somewhat larger than that of the descending leg, means for suspending the granular material in the region of the lower end of the ascending leg, means for feeding a lifting member from the bottom of said descending leg to the region below the bottom of said ascending leg, means for feeding suspending gas to said ascending leg at spaced points along the leg, means for withdrawing granular material from the top of said ascending leg, means for separately withdrawing suspending gas from the top of said ascending leg, and further means for conducting the lifting member from the top of the ascending leg to the top of the descending leg.

4. Apparatus for lifting granular solid material comprising ascending and descending legs of substantially circular cross-section, a series of lifting members of substantially spherical shape located in said descending leg, the diameter of the descending leg being slightly larger than the diameter of the spherical balls, the cross-section of the ascending leg being somewhat larger than that of the descending leg, means for suspending the granular material in the region of the lower end of the ascending leg, means for feeding a ball from the bottom of said descending leg to the region below the bottom of said ascending leg, means for feeding suspending gas to said ascending leg at spaced points along the leg, means for withdrawing granular material from the top of said ascending leg, means for separately withdrawing suspending gas from the top of said ascending leg, and further means foiconducting the ball from the top of the ascending leg to the top of the descending leg.

5. Apparatus for lifting granular solid material comprising ascending and descending legs of substantially circular cross-section, a series of lifting members of substantially spherical shape located in said descending leg, the diameter of the descending leg being slightly larger than the diameter of the spherical balls, the cross-section of the ascending leg being somewhat larger than that of the descending leg, means for suspending the granular material in the region of the lower end of the ascending leg, means for feeding a ball from the bottom of said descending leg to the region below the bottom of said ascending leg, means for feeding suspending gas to said ascending leg at spaced points along the leg in a generally upward direction, the points of introduction of suspending gas being located at alternate sides of the ascending leg, means for withdrawing granular material from the top of said ascending leg, means for separately withdrawing suspending gas from the top of said ascending leg and further means for conducting the ball from the top of said ascending leg to the top of said descending leg.

6. Apparatus for lifting granular solid material comprising ascending and descending legs of substantially circular cross-section, a series of lifting members of substantially spherical shape located in said descending leg, the diameter of the cross-section of the descending leg being slightly larger than the diameter of the spherical balls, the cross-section of the ascending leg being somewhat larger than that of the descending leg, a feeding chamber located below the lower ends of the legs, means within said chamber for suspending a granular material in the region near the lower end of the ascending leg, means for introducing granular material into said feeding chamber, means located in said feeding chamber for transporting singularly the spherical balls from said descending leg to the region just below said ascending leg, upwardly directed conduits located on alternate sides of said ascending leg at spaced intervals adapted to introduce additional suspending gas into the leg, a disengaging chamber located about the upper end of said ascending leg, the ascending leg projecting into the disengaging chamber through the bottom of the chamber in a substantially central location, a generally hemispherical baffle located in said disengaging chamber above said ascending leg, an upper boot projected into the side of said disengaging chamber, and connecting with the top of said descending leg, a downwardly directed screen in said chamber adapted to support balls discharged from said ascending leg and direct them into the upper boot, an upwardly and inwardly directed bafe located inside said disengaging chamber located above the level of the open end of said ascending leg, means defining an outlet for suspending gas from said disengaging chamber located in the region protected by said baille, and means in the bottom of said disengaging chamber defining an outlet for the removal of granular material therefrom.

7. Apparatus for lifting particle-form solids comprising ascending and descending legs, a series of lifting members located in said descending leg, means for suspending the particle-form solids in the region of the lower end of the ascending leg including means for feeding suspending gas to said ascending leg to assist in conveying said particleform solids and said lifting members from the bottom to the top of said ascending leg, means for feeding a lifting member to the region of the bottom of said ascending leg comprising a vessel located below the ascending and descending legs and communicating therewith, a connecting generally hemispherical boot located in said vessel adapted to define a path for the lifting member from the bottom of the descending leg to the bottom of the ascending leg, a serrated wheel horizontally mounted for rotation in said vessel, means for rotating said serrated wheel, the upper portion of said boot being cut away to enable the serrated wheel to pass therethrough, said serrations being adapted to encompass the lifting members and move them singularly to the region below said ascending leg, the lower portion of the boot being removed in the region below the ascending leg to provide an entrance through which the particle-form solids and suspending gas may enter the ascending leg, means for withdrawing particle-form solids from the top of the ascending leg,

References Cited in the le of this patent UNITED STATES PATENTS Lunoe Oct. 13, 1914 Jensen June 24, 1924 10 Hermsdorf Mar. 11, 1930 10 Chawner Oct. 7, 1941 Di Santo Nov. 4, 1941 Anderson Dec. 1, 1942 Cannon Apr. 24, 1945 Wortham Aug. 16, 1949 Bergstrom Mar. 27, 1951 Kirkbride Apr. 3, 1951 FOREIGN PATENTS Great Britain May 5, 1894 

1. APPARATUS FOR LIFTING PARTICLE-FORM SOLIDS COMPRISING ASCENDING AND DESCENDING LEGS, A SERIES OF LIFTING MEMBERS LOCATED IN SAID DESCENDING LEG, MEANS FOR FEEDING A LIFTING MEMBER TO THE REGION OF THE BOTTOM OF SAID ASCENDING LEG, MEANS FOR SUSPENDING THE PARTICLE-FORM SOLIDS IN THE REGION OF THE LOWER END OF THE ASCENDING LEG INCLUDING MEANS FOR FEEDING SUSPENDING GAS TO SAID ASCENDING LEG TO ASSIST IN CONVEYING SAID PARTICLE-FORM SOLIDS AND SAID LIFTING MEMBER FROM THE BOTTOM TO THE OF SAID ASCENDING LEG, MEANS FOR WITHDRAWING PARTICLE-FORM SOLIDS FROM THE TOP OF SAID ASCENDING LEG, MEANS FOR WITHDRAWING 